Mining machine



Oct. 10, 1939. N. D. LEVIN 2,175,507

MINING MACHINE Filed Jan. 17, 1936 6 Sheets-Sheet 1 2G 2G [NI/E/VTOH: 25 M75 D. Lev/r7,

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ATT'Y:

Oct. 10, 1939.

N. D. LEVIN 2,175,507

MINING MACHINE Filed Jan. 17, 1936 6 Sheets-Sheet 4 ATT'Y.

N. D. LEVIN 2,175,507

MINING MACHINE Filed Jan. 17, 1936 6 Sheets-Sheet 5 50 3 7 E 19%| 65 T g t f lllll q G4 e2 QIIIIIIIIIEIIHIIIQLERRZO Ho B E I Q I Mg I07 go 26' 4 I i H, i

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ATT'Y N. D. LEVIN MINING MACHINE Oct. 10, 1939.

Filed Jan. 17, 1936 6 Sheets-Sheet 6 22b //VVE/YTOR: //5 D. Lev/n, BY

Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE MINING MACHINE of Ohio Application January 1'7, 1936, Serial No. 59,558

23 Claims.

This invention relates to a mining machine, particularly of the type adapted to rest on and slide over a mine bottom during cutting operations.

One of the objects of the present invention is to provide a mining machine having a minimum length frame so as to be particularly adapted for use in a system of conveyor mining.

Another object of the invention is to provide a mining machine of the type adapted to rest on and slide over a mine floor, with means for adjusting the height of the cutting mechanism.

A further object of the invention is the provision of a detachable skid to support the mining 1 machine at an increased elevation.

Another object of the invention is to provide in mining apparatus having an electric operating motor, a separate control unit having a flameproof casing slidable over the mine bottom and connected to the kerf-cutting unit by means of an electric cable so that while the kerf-cutting unit is being fed along the working face between the latter and a conveyor parallel to said face, the control unit being located remote from such face, thereby greatly reducing the necessary length of the frame-work supporting the kerfcutting unit.

More particularly it is the object of the present invention to provide a mining machine which is adapted to be employed in a system of conveyor mining, in which the body of the mining machine has a minimum overall length, combined with improved rope feeding mechanism for a cutting unit adjustable in elevation relative to the base frame which rests on and slides over the mine bottom.

Other objects of the invention will appear hereinafter, the novel features and combinations be- I ing set forth in the appended claims.

In the accompanying drawings:

Fig. 1 is a plan View of the mining machine embodying my invention, with the top cover removed to illustrate the operating parts, and with the cutting mechanism cut away to reduce the length of the drawing;

Fig. 2 is an elevational view of the mining machine of Fig. 1 but with the cover plate in place;

Fig. 3 is a plan view similar to Fig. 1 with the cover plate in place;

Fig. 4 is a detailed plan view of the clutch operating mechanism for connecting the drive motor to the cutter mechanism, parts in section being taken on the line 4-4 of Fig. 5;

e5 Fig. 5 is a sectional elevational view taken on the line 55 of Fig. 1, looking in the direction of the arrows;

Fig. 6 is a detailed sectional plan view taken on the line 66 of Fig. 5;

Fig. 7 is a detailed elevational view of the gear engaging mechanism for the feed drum of the mining machine;

Fig. 8 is a detailed sectional elevational View taken on the line 88 of Fig. 1, looking in the direction of the arrows; 10

Fig. 9 is a detailed sectional elevational view taken on the line 99 of Fig. 1, looking in the direction of the arrows;

Fig. 10 is a detailed sectional plan view taken on the line Ill-40 of Fig. 2;

Fig. 11 is a detailed sectional plan view taken on the line ll-ll of Fig. 9;

Fig. 12 is an elevational detail of the mechanism for eifecting operation of the clutch controlling operation of the mining machine; 20

Fig. 13 is a side elevational view of the mining machine opposite to that shown in Fig. 2;

Fig. 14 is a fragmentary View of a structural detail viewed in the direction of the arrows of l4--M as shown in Fig. 13;

Fig. 15 is an enlarged sectional plan view of a portion of the mining machine structure taken on the line |5-I5 of Fig. 13;

Fig. 16 is a diagrammatic view illustrating the feeding movements in shortwall operations of the mining machine embodying my improvements;

Fig. 17 is a plan view of a remotely positioned control mechanism for the mining machine;

Fig. 18 is a side elevational view of the device of Fig. 17; and

Fig. 19 is a wiring diagram showing the control system for the mining machine.

In operating shortwall mining machines in connection with elongated traveling conveyors, it is highly desirable to have the roof props as close to the working face as is permitted by the apparatus used in mining and loading the dislodged coal. The subsidence of the roof back of the roof props, remote from the coal face, can more easily be controlled when the roof props are closer to the coal face and co-operate with the coal vein in sustaining the roof. Furthermore the cost of timbering will be reduced and the safety of mining operations will be increased by preventing the roof from falling where the 0perating attendants must perform their labors.

The distance between the working face and the roof props or posts is determined by the space which is necessary for the elongated face conveyor and the bottom of the mining machine.

The space where the elongated face conveyor and the mining machine operate must be free from roof props but the distance between the roof props and the working face may be reduced to a minimum by the reduction of the length of the frame of the mining machine to a minimum.

Furthermore, where hand shoveling on to the face conveyor is necessary after coal has been shot down, manual labor is reduced by being able to locate the face conveyor closer to the shot down coal. In other words, the reductin of the length of the body of the mining machine to a minimum enables the location of the face conveyor to be made closer to the shot down coal, thereby reducing considerably the manual labor of shoveling the coal.

The mining machine embodying my improvements has therefore been designed with a view of extreme compactness and particularly with a View of maintaining at a minimum the overall length of the body or frame of said machine. It is also desirable to maintain the height of the machine within reasonable limits so as to enable the same to be operated in veins having relatively low roofs. Furthermore, to accommodate the machine to veins of various heights, it is desirable that the elevation of the cutter bar be adjustable with respect to the mine bottom.

Referring to the accompanying drawings, particularly Figs. 1, 2, 3 and 5, the main supporting frame is designated A, upon which is mounted a supplemental frame B carrying substantially all of the kerf cutting mechanism and the means for driving the same. The supplemental frame B together with the kerf-cutting mechanism mounted thereon, constitute a kerf-cutting unit which is adjustable vertically with respect to the main frame A to effect variation in elevation of the kerf cutter.

Secured to the bottom of the main frame A is a bottom skid pan which has an upwardly extending bevelled edge 2| extending entirely around its periphery. This bottom skid pan 20 is adapted to rest upon and slide over the mine floor or mine bottom. The upwardly extending beveled edge 2| facilitates sliding of the pan 20 over the mine floor by preventing the lower peripheral edge of the main frame A from digging into the mine floor.

An auxiliary skid pan 25, having peripheral beveled edges 21, may be detachably secured by means of bolts 26 to' the bottom of the skid pan 20, as shown in Fig. 2, when it is desired to increase the height of reach of the kerf-cutter in its adjustments to top-cutting positions. Rigidly secured to the two forward corners of the bottom pan 2!] and the main frame A is a pair of vertical standards 22 and 23. A similar vertical standard 24 is located centrally of the rear end of the main frame A as shown in Fig. 1. It should be understood that the standards 22, 23 and 24 which are spaced apart triangularly as shown in Fig. 1, are rigidly secured to the main frame A and always move bodily therewith.

The vertical standards 22, 23 and 24 are each of box-like structure closed on their outer sides but open on their inner sides facing the kerf-cutting unit to receive the horizontal extensions from the horizontal bottom plate 28 of the kerfcutting unit. These extensions fit in the standards to slide vertically along the same and are held in interlocking relation therewith against relative lateral movements by vertical shoulders and vertical flanges. The vertical shoulder for the standard 22 is shown at 22' in Fig. 15 and the vertical flange at 22", Fig. 15 being a sectional plan view taken on the line |5|5 of Fig. 13. Since the standards 22, 23 and 24 are similar in construction, each has such a vertical flange and such a vertical shoulder. The vertical shoulder for the standard 23 is illustrated at 23 in Fig. 2 and the vertical shoulder for the standard 24 is illustrated at 24 in Figs. 2 and 5. Such interlocking relation between the bottom plate 28 and the standards 22, 23 and 24 against relative lateral movements permits the transmission of feeding strains directly from the frame of the kerf-cutting unit directly to the base frame on which the standards are mounted or to distribute such feeding strains between the screw posts 3|, 3|, 3|" and the interlocking connections between the extensions from the bottom plate 28 and the inner walls of the box-like standards, as illustrated in Fig. 15. Moreover, by making the extensions from the bottom plate 28 horizontal the bottom of the kerf-cutting unit may be adjusted to a very low position when desired.

The standards 22, 23 and 24 are arranged as shown in Fig. 1 and each has associated therewith screw-threaded elevating mechanism for adjusting the elevation of the kerf-cutting unit comprising the supplemental frame B.

The elevating mechanism for the kerf-cutting unit comprises stationary screw posts 3|, 3| and 3| which are rigidly secured to the standards 24, 23 and 22 respectively. At the top of each standard is a removable cap plate 30 and to this plate is secured clamping means 32 associated with the upper squared end of the screw-threaded post. This construction is shown in plan in Fig. 1 for the standard 24, and similar mechanism is associated with each of the other standards 22 and 23.

By referring to Fig. 5 it will be seen that at the lower end of the screw-threaded post 3| is a nut 33 having a circular flange 34 adapted to cooperate with a circular recess or ring seat 35 about an aperture 36 in the bottom plate 28 of the supplemental frame B. A retaining ring 31 is located on top of the rotary nut 33 and by means of bolts, as shown in Fig. 5, the ring 31 is locked in place and at the same time the sprocket 38 is secured to the rotary nut 33.

It is evident that the nut 33 is rotatable with respect to the bottom plate 28 within the aperture 36 so that when rotated by power transmitted to the sprocket 38, the nut 33 will travel vertically along the screw-threaded post 3| and will carry with it the bottom plate 28, there being rotary nuts, similar to that designated 33, associated with the vertical screw posts 3| and 3|". All of these rotary nuts are rotated simultaneously by means of the endless sprocket chain 39 which meshes therewith.

In view of the fact that each screw post 3|, 3| and 3|" is provided with elevating mechanism, the kerf cutting unit may readily be adjusted in elevation relative to the main frame A. The path of the endless drive sprocket chain 39 is outlined in Fig. 1 and the connection of this drive chain to the source of power for operation thereby will be explained more fully hereinafter.

The apparatus for moving the machine over the mine bottom comprises a rope drum 40 mounted as shown in Fig. 1 to rotate on a horizontal axis extending transversely of the supplemental frame B. Connected to and wound on the rope drum 40 is a feed rope or cable 4| which reaches from the lower periphery of the rope drum 40, as shown in Fig. 13, so as to extend horizontally around the forward guide pulley 42, as shown in Figs. 1 and 3. Fig. 13 being an elevational view of that side of the machine carrying the rope drum 40, shows that the rope 4| extends horizontally in a hori zontal plane adjacent the bottom plate 28 of the supplemental frame B. It will thus be seen that the rope feeding mechanism, as well as the kerfcutting mechanism, is mounted on the supplemental frame B and moves bodily therewith when the kerf-cutting unit is adjustable in elevation relative to the main frame A.

When the free end of the feed rope 4| is anchored, as illustrated at 4| in Fig. 16, the mining machine is in position for a short-Wall operation along the working face. In performing this operation, however, a retarding rope drum 43 is connected in co-operative relation with the feed rope drum 40, by having the rope 44 connected thereto and wound thereon and then extended around a guide pulley 45 to an anchorage 44' in the mine, as illustrated in Fig. 16. The retarding rope drum 43 is mounted on the supplemental frame B to rotate relatively thereto on a vertical axis. Both the feed rope drum and the retarding rope drum 43 are therefore mounted on the supplemental frame B and therefore move bodily with the kerf-cutting unit when the latter is adjusted in elevation relative to the main frame A.

The kerf-cutting unit comprises an elongated cutter bar 46 on the periphery of which is guided an endless chain cutter 41 comprising spirally arranged cutter bits 48. The elongated kerf-cutter comprising the cutter bar and the endless chain cutter 41, is mounted on top of the supplemental frame B to occupy a top cutting position. That is to say, the machine illustrated is adapted to cut a kerf adjacent the roof of the mine vein in a plane extending through the top of the machine.

The driving sprocket 49 for the endless chain cutter 41 is provided with bearings to support the same for rotation about the vertical axis of the stationary bearing I59 which is secured between the top plate 45 and the upper side of the motor frame, as shown in Fig. 5.

As best illustrated in Figs. 2 and 3, the top of the frame B is provided with a cover plate 59 which extends under the rear portion of the endless cutter chain so as to have a receiving opening adjacent to the post 22, for the cuttings swept from the kerf rearwardly. Inasmuch as that end of the frame B is adjacent to the coal face during operation of the kerf-cutting mechanism, the cuttings will be swept by the rapidly traveling chain cutter directly from the kerf into the pan 50 and such cuttings Will be guided along the upstanding edge wall 50 into the chute 50" for ejection therefrom directly to the endless traveling face conveyor [64, as diagrammatically illustrated in Fig. 16. The rearwardly extending chute 59" may be downwardly inclined as illustrated in Fig. 2. It should be particularly understood that irrespective of the elevation of the kerf cutter, the cuttings produced thereby will be automatically transferred along the top of the machine to the rear inclined chute 59 for continuous delivery to the traveling face conveyor l6l during feeding movements of the mining machine transversely of itself during such shortwall operations as illustrated in Fig. 16.

I will now describe the power transmission mechanism and its compact arrangement and association with the supplemental frame B, that render possible the great reduction in the overall mounted upon ball-bearings 52 carried by the motor housing or field frame 28. Keyed to the motor shaft 5| is a bevel gear 53 located above the oil sump 54 at the bottom of the gear housing 56. The bevel gear 53 meshes with a fiber gear 55 which is journaled on the bearing 54. The fiber gear 55 thus becomes effective to lift oil from the sump 54 to lubricate the bevel gear 53 and thereby maintain constant lubrication of the gears within the gear housing 56. A removable plug, not shown, may be provided in the housing 56 to supply oil to the sump 54. The bearing 54' may be held in place by means of a set screw 55'. The removability of the bearing 54 facilitates assembly and renewal of the fiber gear 55.

The bevel gear 53 meshes with the bevel gear 51 which is mounted as shown in Fig. 8 for rotation on a vertical axis. The bevel gear 51 is connected to a sleeve 58 which is keyed to the depending shaft 6! to the upper end of which is secured the spur gear or pinion 62. The sleeve 58 is journaled to the supplemental frame B by means of the spaced-apart thrust roller bearings 59, 59. It should be understood that the sleeve 58 and the shaft 55 are connected to rotate together as a stub shaft connecting the bevel gear 57 to the pinion 62. This stub shaft may be provided with appropriate grease conduits and fittings 63 for supplying lubricant to the thrust bearings 59, 59.

It can readily be seen by referring to Figs. 1 and 5 that the electric motor is located at the front end of the frame B directly under the rear end of the elongated chain cutter, and that the power transmission mechanism shown in Fig. 8 is connected to the advancing side of the machine for operation from the motor shaft 5| which is rotated by means of the motor armature 29 on an axis which is parallel to the working face or transverse of the supporting framework, as illustrated in Fig. 16. Fig. 1 shows the pinion 62 in plan exposed to view since the cover 50 of Figs. 3 and 8 has been removed in Fig. 1 for the sake of illustration. The pinion 62 meshes with and drives a large ring gear 6-4 which is rigidly attached to the dished wheel 65, as shown in Figs. 5 and 8.

The wheel 65 is provided with a hub 66 which is journaled on the bushing 61 secured to the vertical bearing or stub shaft 159, the latter being in turn secured to the top plate t6 and the supplemental frame B.

Keyed to the lower end of the hub 66 is a driv ing pinion 58 which meshes With a gear 69, as shown in Figs. 1 and 5. Also journaled on the hub 66 is a clutch operating disc NJ, as shown in Figs. 4 and 5. The clutch operating disc carries a plurality of circumferentially spaced vertical pins H adapted to project through bushed apertures 12 in the dished Wheel 55 so as to project into recesses 13 in the lower side of the chain driving sprocket 49.

As best illustrated in Fig. 4, the clutch operating disc 19 may be lifted or lowered by means of an cutter.

operating handle 14 which is retained in an adjusted position by releasable lock mechanism I5. The handle 14 is connected through a rock shaft 16 to a shipper 10 which is connected at diametrically opposite sides to the clutch element 18, as shown in Fig. 4.

It is evident that when the disc 18 is in the position illustrated in Fig. 5, there will be no driving connection from the motor to the chain However, if the handle 14 is actuated to throw in the clutch to connect the power transmission mechanism to the sprocket 49, the chain cutter may be driven in the desired direction under the control of the motor controller illustrated at |6| in Figs. 1 and 3.

It should be understood that the electric motor shown in sectional elevation in Fig. 5 is reversible and may be operated in either direction at various speeds, but when the feeding movement is in the direction of the arrow I62 of Fig. 3 the chain should be driven in the direction of the arrow |63 so that the cuttings may be swept out of the kerf on the leading edge of the kerf-cutter, and, as above explained, the rapid travel of the chain cutter will sweep most of the cuttings along the cutting chute at the top of the machine. These cuttings will be directed by the inclined portion 58" of the chute on to the face conveyor I64, as shown in Figs. 2, 3 and 16.

A main line switch for connecting the supply mains to the electric motor may be enclosed in a casing or switch box I65 and such switch may be closed by means of a handle N36. The motor is entirely enclosed so as to be flame-proof but access to the same may be had by authorized persons through the hole normally closed by the removable cover plate I61. Direct access to the commutator and brushes of the motor may be had by authorized persons by removing the cover plates I68. The shaft |5| may have a lubricating connection as illustrated at I69. It should be understood that in gaseous mines the main line switch, the controller |6|, and the motor armature 29 together with its commutator and brushes are enclosed to render all arcing flame-proof.

By referring to Fig. 5 it will be seen that at the lower center of the horizontal gear 69 is located a pinion 18 which may be welded to the gear 69 so as to rotate at all times therewith. The pinion 18 is keyed to the upper end of the vertical hollow shaft 88 which is journaled in ball-bearings 8| and 82 on the supplemental frame B. The upper end of the hollow shaft is threaded to receive an adjusting nut 83 which may be operated to adjust the vertical shaft 88 with respect to the upper bearing 8|. A screw 84 is provided for maintaining said adjusting nut 83 in any one of a plurality of fixed positions of adjustment.

The lower end of the hollow shaft 88 carries a cone clutch element 85, preferably made of brass, which is held on said shaft by washer and screw mechanism 86. Co-operating with the cone clutch element 85 is a cone clutch element 88 preferably covered with appropriate friction material. Connected to the cone clutch element 88 to rotate therewith is a sprocket 81 which is pivoted to the lower end of the rod 98.

The sprocket 81 meshes with the endless elevating chain 39. As outlined in Fig. 1, the chain 39 is reeved about the driving sprocket 81 around the idler 89 and each of the sprockets 38 associated with the rotary nuts 33 on the vertical screw posts 3|, 3| and 3|.

It is evident that whenever the electric motor shaft 5| rotates, power will be transmitted through the gearing shown in Fig. 8 to the gear 69 shown in Fig. 5 irrespective of the driving of the chain cutter. It will thus be seen that when the cone clutch 85, 88 is thrown in While the motor is operating, the chain 39 will be driven to vary the elevation of the supplemental frame B relative to the base frame A. Whether an elevating or lowering operation takes place in response to the driving of the chain 39 will depend upon the direction of rotation of the electric motor which, as before stated, is of the reversible type.

The cone clutch 85, 88 may be operated by actuating the vertical rod 98 which extends through the hollow shaft 88 and is attached at its lower end to the center of the sprocket 81 as shown in Fig. 5. This may be effected by means of a nut screw-threaded on the lower end of the rod 90 so as to clamp the center plate of the gear 81 to a circular shoulder near the lower end of the rod 1 98. The rod 98 will thus be connected to the sprocket 81 to rotate therewith while journaled in the hollow shaft 88.

The mechanism connected to the upper end of the actuating rod 98 for lifting and lowering the latter to operate the cone clutch 85, 88, is shown in detail in Figs. 5 and 12. The upper end of the rod 98 is mounted in a cup 9| containing a ball bearing 92. The cup 9| is carried by the vertical arms 93 pivotally connected at 95 to the T-shaped link 94, the upper end of which is pivoted at 96 to an eccentric 96 at one end of a shaft 91 which is journaled in the bracket I10, as shown in Fig. 12. The shaft 91 may be rocked by means of a lever 98. When this lever is depressed as viewed in Fig. 5, the actuating rod 98 will be lifted to apply the cone clutch 85, 88 for transmission of power through the hollow shaft 88 to the sprocket 81 and. the elevating chain 39. By releasing the lever 98 or giving it a positive upward movement, the cone clutch element 8'! may be released from the upper cone clutch element 85 to effect discontinuance of the lifting or lowering action, whereupon the nuts 33 on the screw-threaded posts will lock the frame B in adjusted position relative to the base frame A against either up or down relative movement during feeding operation of the kerf-cutter by means of the rope gearing diagrammatically illustrated in Fig. 16.

It should be particularly noted that the vertical hollow shaft 88 is necessary for transmitting power from the motor to the rope drums 48 and 43. This vertical hollow shaft is located in close proximity to the rear end of the motor and its length is no greater than the vertical dimension of the motor frame.

The rope gearing for effecting feed of the kerf cutter along the face as illustrated in Fig. 16, comprises the feed rope drum 40 and the retarding rope drum 43. The pinion 73 shown in sectional elevation in Fig. 5 meshes with the large horizontal gear wheel 19 as outlined in Fig. 1. The details of construction of the power transmission mechanism between the gear 19 and the rope drum 43 are shown in sectional elevation in Fig. 9. The gear 19 is provided with a depending hub |1| which is journaled in the bushing 19' secured to an opening in the frame B. The gear 19 is keyed to the vertical shaft 99, as best seen in Figs. 9, 10 and 11. This shaft 99 is suitably mounted in appropriate journals I88 and IUI, the former of which is attached to a planetary gear spider I82 and the latter of which is attached to a cup-shaped bearing support I83 rigidly attached to the bed plate 28 of supplementary frame B. Rigidly attached to the shaft 99 is a sun or central pinion gear I04 which drives a plurality of planetary gears I05, each of which meshes with a ring gear I06 rigidly attached to the handling drum 43. The planetary gears I05 are loosely carried on suitable stub shafts I'I rigidly attached to the planetary gear spider I02. Said planetary gear spider I02 carries a brake drum I08 with which cooperates a brake band I09 provided with suitable brake lining 0. It is evident that the shaft 99 is directly driven from the motor 29 and always rotates when said motor 29 rotates. To effect a driving connection between said shaft 99 and the handling drum 43, it is necessary to retard the movement of the brake drum I08 in a manner which will be understood by referring to Figs. 6 and 10. This driving connection between said shaft 99 and the handling drum 43 is preferably not of a positive character as it should be understood that slippage between the brake drum I08 and the brake lining III] is provided for and that by adjusting the clamping action of the brake band I09 on said brake drum I08, the handling drum 43 may be driven at varying speeds.

When the machine is operating to perform a kerf-cutting operation while the drum 43 is acting to guide the cutter bar along a path trans- 3 versely of itself, it is necessary that the said drum the driving connection between the shaft 99 and the handling drum 43 is effective to reel in the cable 44 rather than to pay out said cable. Under these conditions, the braking action of the brake band I09 is effective more as a brake to maintain cable 44 at the proper tension rather than to effect an operative connection between the shaft 99 and said drum 43. This particular type of planetary clutch mechanism is very effective to perform in this dual capacity; namely, either as a clutch to effect a driving connection between shaft 99 and drum 43 or as a brake to retard the rotation of drum 43 and to maintain the desired tension on cable 44.

It is evident that, so long as the brake drum I38 is free to rotate and there is any appreciable load on the handling drum 43, rotation of the shaft 99 will result in the rotation of said brake drum I08 while said handling drum 43 remains stationary. The braking of the brake drum I08 will result in a transmission of the motion of shaft 99 to the handling drum 4'3 and the speed of rotation of the drum 43 will be controlled by the amount of slip permitted between the brake H0 and the drum I08. (Kl

,jacent the room face and positioned forwardly of the mining machine. It may also be necessary to attach cable 44 to a mine jack forward of the machine and on the other side thereof. Both of the cables 4| and 44 then extend from .the machine to mine jacks on opposite sides of the cutter bar 46.

Drum 40 is then operatively connected to the motor 29 to operate at a definite speed while the cutter chain 41 revolves, and ii drum 43 is also employed, sufficient braking action is applied to drum I08 to guide the cutter bar 46 properly into the room face. It will be obvious that fast drum 43 will not be directly connected to the motor 29 in performing this operation for such a connection would cause it to rotate at a speed in excess of that desired.

When the cutter bar 46 has been sumped in, cables 4| and 44 will be removed from the jacks and cable 4| will be attached to a jack 4| (Fig. 16) positioned toward or near the room rib at the left hand end of the room and cable 44 will be attached to a jack 44 positioned near the right hand room rib. An operating connection will then be effected between said feed drum 40 and the motor 29 with the cutter mechanism operating while the mining machine is drawn laterally of the room across the face thereof with the cutter mechanism cutting a kerf adjacent the roof of said room and across said face. During this operation drum 43 will be operated to perform a retarding function, as above described, to maintain the cutter bar 49 substantially perpendicular to the room face to insure the cutting of a proper kerf.

After the kerf is substantially completely cut, jacks 41 and 44' will be moved to a position rearwardly of the mining machine, as illustrated at the top of Fig. 16, and drums 40 and 43 will be operated, to slide the machine rearwardly to finish cutting the kerf. In this action drum 43 will aid drum 40, and clutch drum i118 will only have a limited amount of friction applied there to, as aforesaid.

It is also to be noted, that, as best seen in Figs. 1, 13 and 15, the pulley 42 is swingably mounted by being journaled on a shaft 42! to which it is held by washer 32! and pin 322, which shaft 42I is carried on an arm 422 pivoted to the bottom of supplementary frame B by a horizontal pin 423 carried between bracket arms 424 rigidly attached to said supplementary frame B, as by welding.

Instead of attaching the free end of cable 4| directly to a mine jack 4|, it may be desirable to attach a pulley to said jack and to reeve said cable 4| about said pulley and return it to the mining machine to which its free end will be anchored. This is particularly desirable where the coal is hard and there is a tendency for the cutter bar 46 to tilt due to the cable 4| pulling on the bottom of the mining machine. I therefore provide a hook 425 (Figs. 1, 3, 14 and 15) adjacent the top of supplementary frame B which is adapted to receive the free end of cable 4|, thus providing a pull at both the top and bottom of the mining machine to maintain the cutter bar horizontal when cutting a kerf. It will be evident that the arm 422, being freely pivoted about the horizontal axis of pin 423, will pivot to a position to provide for the proper reeving of cable 4| about the pulley 42 regardless of the elevation of said pulley and regardless of the slope of the cable 4|, which slope will be determined by the distance of the mining machine from the jack 4 I the elevation at which it is anchored or otherwise attached thereto, and the height of pulley 42, which varies with the elevation of supplementary frame B.

The brake band I09 is provided with a pair of shoes II I and I I2, the former of which is adapted to be held in an adjustable fixed position by adjusting screw ||3 carried by the supplementary frame B. Cooperating with the shoe H2 is an adjusting mechanism for tightening the brake band I09 to impede the rotation of brake drum I08. This means comprises an abutment screw 4 adapted to hear at one end against the shoe H2 and screw-threadedly received in a threaded sleeve II5 whereby, upon rotation of said sleeve H5, the abutment screw II4 will be adjusted longitudinally with respect thereto. The head I I6 of said abutment screw H4 is squared and is received in a square groove in said shoe I I 2 whereby rotation of said screw H4 is prevented. Keyed to the sleeve II5 for effecting rotation thereof is a gear I I! which is retained on the supplementary frame by a bracket H8, best seen in Fig. 9. The gear in bears against the surface II 9 on the supplementary frame B. If desired, an anti-friction bearing may be placed between said gear I I I and said surface I I 9 to reduce the force necessary to clamp the brake band I69. Meshing with the gear II? is a drive gear I20. The gears I I7 and I20 may be in 1 to 1 ratio but it is preferred that gear I20 be smaller than gear II'I whereby an advantage will be gained through said gears. If necessary to obtain still greater advantage, three gears may be employed instead of the two illustrated; that is, a greater reduction can be provided between the first and last gear of the train than is provided by only two gears. Drive gear I20 is driven from shaft I20, seen in Figs. 6 and 10, the construction of which will be described more in detail hereinafter.

Referring particularly to Figs. 1, 5, 6 and 7, there is illustrated the mechanism for effecting a driving connection between the motor 29 and the feed drum 40 and the operating mechanism for the planetary clutch illustrated in Figs. 8, 9 and 10 for effecting a connection between motor 29 and the handling drum 43. As best seen in Figs. 5 and 6, the shaft 85 which, as was above pointed out is driven from motor 29, carries an integral worm I2I which meshes with worm gear I22. Worm I2I and worm gear I22 are carried in a split housing formed by a pair of brackets I23 and I24 (Fig. 6) which are bolted rigidly with the upright wall I25 (Fig. 6) of the motor housing, which wall I25 is rigidly attached to the bed plate 20, as by welding. It may be here noted that this wall I25 therefore not only constitutes a housing for the motor 29 and provides a magnetic path for the flux of said motor but, in addition, comprises a part of the frame structure of the supplementary frame B. The brackets 23 and I24 provide journal bearings I26 and I2'I (Fig. 5) for supporting the shaft 80. Bracket I23 is also provided with an inwardly extending sleeve I28 (Fig. 6) which carries a bushing I29. The bottom portion of the brackets I23 and I24 are rigidly attached to the bed plate 28 and are attached together by appropriate nuts and bolts.

Adjacent the left hand rear side of the sup plementary frame B as viewed in Figs. 1 and 6, there is provided an integral upwardly extending bracket I30 provided with a bushing I3I. Between the bushings I 29 and I3I extends a hollow shaft I32. Near the left hand end of shaft I32, as viewed in Fig. 6, there is provided a pinion gear I33 which is keyed to said shaft. Said pinion I33 is adapted to mesh with a gear I 34 cut in a flange of feed drum 40. A mechanism is provided for effecting the engagement or non-engagement of gears I33 and I34 whereby the feed drum 40 may be free to rotate on its shaft or may be in driving relation with the shaft I32 whereby rope or cable M can be pulled out manually and its free end connected to an anchorage in the mine extraneous to the machine, or for any other desired purpose where drum 40 should be free to rotate.

It is, of course, evident that in order to feed the machine by employing the drum 40, driving engagement between the gears I33 and I34 is necessary.

The means for effecting the engagement and disengagement of said gears I33 and I34 will now be described. Referring particularly to Figs. 6 and 7, a stub shaft I35 is provided which is rigidly attached to bracket I30 of the supplementary frame B. At the left hand end of the shaft I35, as viewed in Fig. 6, there is provided a circular disc I36 having a pair of peripherally spaced notches I31 and I38. Journaled on the shaft I35 is an eccentric sleeve I39 to which is connected an operating arm I40 provided with a spring pressed detent I4 I. Surrounding the eccentric sleeve I39 and carried on the interior circumference of the feed drum 40 is a bushing I42. It is evident that by rotating arm I40 the eccentric sleeve I39 will be effective to move the drum 40 bodily together with the gear I 34 toward or away from the gear I 33. With the arm I40 in the position illustrated in Fig. 7, the gears I 33 and I34 will be meshed and with the spring pressed detent I4I engaging the notch I38, said gears I33 and I34 will be maintained in engagement. By lifting the spring pressed detent HI and rotating the arm I40 until the detent I4I snaps into the notch I 31, the gears I 33 and I 34 will be disengaged and will be maintained in the disengaging relation. In order to reinforce the flange of feed drum 40 in which gear I34 is cut reinforcing brackets I43 are provided.

For effecting a driving connection between the worm gear I22 and the shaft I32, the former of which, as is evident from the previous description, is driven from the motor 29, a friction clutch is provided which is best illustrated in Fig. 6. This clutch comprises a rotor I44 keyed to the shaft I32 and carrying a plurality of discs I 45, A clutch housing I46 has an extending sleeve I41 which sleeve is keyed to the worm gear I22 adjacent its outer periphery and is loosely mounted on a bushing I48 mounted on the outside of the sleeve I 28 of bracket I 23. Said housing I46 carries a plurality of discs I49 which are splined to said housing I46 and which interleave with the discs I carried by rotor I44. It is evident that if the splined discs I49 are compressed in the housing I46, there will be a frictional engagement between said discs I49 and the discs I45 whereupon the rotary motion of the housing I 46, which is transmitted thereto by the worm gear I22, will be imparted to the shaft I32. Adjacent the left hand end of the housing I45 there is provided a cover plate I50 having an internal screw-threaded throat I5I adapted to receive the screw-threaded hub I5I of an operating hand wheel I52. Within the housing I46 is a thrust collar I53 having a sleeve I54 loosely mounted on a bushing I55, which bushing is loosely carried on shaft I32. A bushing I 56 is also provided between the sleeve I54 and the hub I5! of the hand wheel I52. The cover plate I50 will, of course, be rigidly bolted to the housing I46 and form a part thereof. Between the hub I 5| and the thrust collar I 53 there is provided an anti-friction bearing I57. It will be evident that upon the turning of the hand wheel I52 with respect to the housing I46, the hub I5I' will force the thrust collar I53 to the right as viewed in Fig. 6, whereupon said thrust collar I53 will eifeet an operative engagement between the housing I46 and the rotor I44 due to the frictional engagement of the discs I45 and I49. It is therefore evident that hand wheel I52 may be operated to efiect an operative connection between the motor 29 and the feed drum 40. Due to the fact that this feed drum is driven through a number of reduction gears from the motor 29, its speed of rotation will be very slow for feeding purposes. It may be noted that hand wheel I 52 rotates with housing I46 but there is no olifiiculty involved in operating it as this speed of rotation is relatively slow.

The shaft I82 is made hollow to receive an operating shaft I28 which is the shaft for operating the planetary clutch mechanism shown in Figs. 8, 9, 19 and 11 for effecting a driving connection between the motor 29 and the handling drum 43. It may be mentioned that the reduction between said motor 29 and the handling drum 43 is considerably less than the reduction between the feed drum 48 and the motor 29. This is desirable because a rather rapid handling rate is preferred in order that the machine may be moved to position at a rapid rate, while the feeding rate of the machine must be consistent with the necessary cutting speed which is, of course, a relatively slow speed. The shaft I29 is provided with an operating hand wheel I58. It is thus obvious that by operating the hand wheel I58, the brake band I 99 (Fig. 10) may be clamped about the brake drum I98 to effect a variable driving connection between the shaft 99 and the handling drum 43 or for effecting a braking action on the handling drum 43.

It is evident that the hand wheel I58, the detent I4I, the hand wheel I52, the handle 14 and the lever 98 are all positioned at one station where they may be easily reached and operated by a single operator. It is also evident that the elevating mechanism which is controlled by the lever 98, the kerf cutting mechanism which is controlled by the handle 14, the feed drum 49 which is controlled by the hand wheel I52 and the handling drum 43 which is controlled by the hand wheel I58 may each be operated directly from the motor 29 independently of the other operating mechanism without regard to the operating or non-operating condition of any of said other mechanisms. This is particularly desirable with respect to the cutter mechanism for it is desirable that this cutter mechanism be disconnected when a handling operation is being performed by the machine. It is, of course, a source of danger if the cutter mechanism is operating when the machine is not performing a cutting operation.

It is evident that the device of my invention comprises a very compact kerf cutting machine which has a minimum of overall length and height and a minimum of weight, yet is extremely flexible in its possible modes of operation. This results from the numerous structural details above described. In addition, it should be pointed out that the frame of the motor 29 constitutes an integral part of the supplementary frame 13. That is, the bed plate 28 is an integral part of the motor housing of magnetic material and serves a dual function of a supporting bed plate and motor housing providing a magnetic path for the flux of said motor. The wall I25 of the motor 29 likewise constitutes supporting means of the supplementary frame 13 as well as a housing for the motor and providing a magnetic path for the flux thereof. The top and forward walls of the motor housing also constitute integral parts of the supplementary frame B, said top portion directly supporting a stub shaft I59 which supports the journal 61 as well as the sprocket 49 and hub 86 of wheel 65. The forward wall of said motor 29 comprises a direct support for the cutter bar 46 and said cutter bar 46 is rigidly attached thereto by heavy nuts and bolts I69.

Having provided a mining machine of minimum dimensions possessing the numerous features of adjustment above described, I provide a control system therefor which maintains the compact nature of said mining machine. To this end I provide the larger control elements such as the starting resistor and the operating relays in a separate housing which is positioned remotely from the mining machine and is connected thereto by electric cable.

As best seen in Figs. 16, 17, 18 and 19, a housing I15 is provided within which is contained the operating relays and the resistor for the motor circuit. Referring particularly to Figs. 1'1 and 18 said housing I 15 is mounted upon a bottom plate I16 having handles I11 at each end thereof. Mounted upon the bottom plate is a compartment I18 having a removable cover plate I19 within which compartment I18 may be housed a resistor I89 (Fig. 19). A second compartment i8l is mounted upon bottom plate I15 and houses the other elements of the control system which will be described in detail hereinafter.

The compartment I8I is provided with a removable cover plate I82 having lifting handles I83, I83. Removable plugs I84 are also provided in the cover plate I82 which may be removed to permit access to certain relays therein without requiring the removal of the entire cover plate I82.

Mounted upon the mining machine is a closed control box I85 within which is housed a pair of switches, one of which is a reversing switch I86 (Fig. 19) operable by lever I81 (Figs. 1, 3 and 13, the other of which is a multiple circuit con trol switch I88 (Fig. 19) operable by a lever I89 (Figs. 1, 3 and 13), said levers I81 and I89 comprising the motor controller indicated generally by I8I.

Extending between the control box I85 and the housing I15 is a cable I99 (Fig. 16) whereby the operation of the control switch I88 at the mining machine will operate certain means within the housing I15, as will be hereinafter described, to control the electric motor 29.

The reversing switch I86 merely determines the direction of rotation of motor 29 under the control of control switch I88. If desired, the cable I99 may be built into two strands HI and I92, the former of which carries the power cables, and the latter of which carries the control cables. As illustrated in Figs. 1'1 and 18, strands I9I and I92 of cable I98 may be rigidly attached to the bottom plate I16 of housing I15 by clamping means I93 mounted upon bracket I94. The control circuit for the mining machine is illustrated in Fi 19.

The operation of the mining machine will be best understood from a description of a typical cycle of movement thereof. Assuming the parts in the positions illustrated in Fig. 19, if it is desired to start the motor 29 lever I89 will be moved so that a bridging conductor portion I95 thereof will bridge stationary contact I96 and elongated arcuate stationary contact I91. As a consequence, current will flow from the power line I98, through main line or cut-out switch I99, through solenoid 299 of the overload relay 20I, over conductor 292 of cable I90, and through safety switch 293, which, as may be seen from Fig. 2 of the drawings, is operable from the trailing side of the mining machine as the operating lever therefor extends through the end plate of motor 29. From said safety switch 293 conductor 292 leads to contact I91. The circuit then therefore continues from contact I91 through bridging conductor I95, contact I99, conductor 294 of cable I99, through limiting resistor 295, solenoid 296 of the overload release mechanism of overload relay 29I, and thence to the other power line 291 through switch I99. As a consequence of the bridging of contacts I96 and I91, solenoid 296 will be energized to release overload relay 29I, in case contacts 299 and H9 have been opened in response to an overload condition which will be described more completely hereinafter.

Upon further movement of the lever I89 contact I91 will be connected to contact 2 by the bridging conductor I95, whereupon the circuit will be completed from said contact I95, as above traced, to said contact 2 over conductor 2I2 of cable I99 through contacts 299 and 2I9 which are now bridged by conducting strap 2 I 3, to solenoid 2I4 of starting relay 2I5, and thence to power line 291. This will energize solenoid 2I4, lifting the armature 2I6 of starting relay 2I5 to bridge contacts 2I1, 2I8 thereof by conductors 2I9 and 229 respectively. The bridging of contacts 2I1, 2I8 will close the circuit to the motor 29 from power line I98 through solenoid 299, through contacts 2I'I, conductor 22I, resistor I89, conductor 222 of cable I99, reversing switch I86, one side of armature of motor 29 to the other side of the armature of motor 29, through reversing switch I86, series field 223 of motor 29, conductor 224 of cable I99, and contacts 2I8 of starting relay 2| 5 to power line 291.

It will also be noted that a shunt field 225 is provided for the motor. 29 which is at this time connected directly across conductors 22I and 224. Under these conditions the motor will be started with the resistor I89 in series with the motor armature. It will, of course, be evident that the motor is of the compound wound type. It is also to be noted that the direction of rotation of the motor will be determined by the position of the reversing switch I86.

After the motor has started as above described, the lever I89 will be moved to the final or running position in which the bridging conductor I now connects the contact 226 to the contact I91. As a consequence, the circuit will be provided to solenoid 221 of running relay 228 over the circuit previously traced, to contact I91, over bridging member I95, contact 226, conductor 229 of cable I99, solenoid 221, conductor 239, to power line 291. When solenoid 221 is thus energized it will lift the armature 23I thereof to close contacts 232 bridged by conductor 233. The bridging of contacts 232 by conductor 233 merely shunts the resistor I89 over conductors HI and 234. As a consequence, full line voltage will be applied to the motor 29 and said motor will operate at its running speed.

It may also be mentioned that the cable I99 includes a conductor 235 which connects or grounds the housing I15 to the mining machine framework thereby to insure that they are at the same potential.

In order to protect the motor against a condition of continuous overload, the overload relay 29I is adapted to shut down said motor whenever an overload condition persists for a predetermined time. To this end overload relay 29I includes an armature 236 associated with solenoid 299 to the end of which armature is connected a dash pot 231 which restricts the upward movement of said armature 236 but permits free and rapid downward movement thereof. Armature 236 also carries an upwardly extending pin 231 adapted to strike an insulating block 238 carried by the conducting strap 2I3 which is pivoted at 239. The strap 2I3 also carries a projecting arm 249 which is insulated therefrom, which carries at its end a retaining latch member 24I.

Associated with the previously mentioned solenoid 296 of the overload relay MI is an armature 242 which is biased to a bottom position by an adjustable means including a spring 243. A downwardly extending shaft 244 is connected to said armature 242 and is provided with a retaining latch member 245 adapted to cooperate with the latch member 24I to hold the strap 2I3 in position to break the contacts 209 and 2H) whenever strap 2I3 is pivoted about the pin 239 in response to an overload condition, as previously described. As a consequence, whenever an overload condition persists for a predetermined time, overload relay 29I will operate to open contacts 299, 2I9, thereby to de-energize relay 2I6, which, whenever de-energized, will shut down the motor 29. Overload relay 29I maintains the contacts 299, 2I9 open until the operating lever I89 is returned to the non-operating position, thereby preventing the restarting of the motor 29 except in the usual manner. It will, of course, be evident that the power lines I98, 291 will elfect a connection from any primary source of electric power to the control mechanism within housing I15 over the usual type of electric cable. It is thus evident that by positioning the larger and bulkier portions of the control system at a remote position I maintain at a minimum the size of the mining machine, which must be positioned between the face conveyor and the cutting face of the mine room.

To review briefly the mode of operation of the mining machine with particular reference to Fig. 16, a face conveyor I64 will be positioned parallel with the face of a mine room which is to be cut away. This face conveyor I64 will feed a room conveyor I14 which removes the coal from the mine room. To start the kerf cutting operation on the room face, the mining machine is positioned at one corner of the mine room, for example, the lower right hand corner of Fig. 16, and the cables M and 44 are anchored forwardly of the mining machine and at each side thereof. The driving connection will then be effected between drum 49 and the motor of the mining machine and a slipping connection will be effected between the drum 43 and said mining machine motor. The driving connection will also be effected between the mining machine motor and the kerf cutter chain. The kerf cutter will thus be sumped into the mine face. After this sumping operation has been completed, cable M will be anchored to a jack, such as 4|, positioned toward the opposite rib of the mine room, and cable 44 will be anchored to a jack, such as 44, adjacent the mine rib where the sumping operation has been performed. Power will again be applied to the drum 49 and to the kerf cutting chain while the friction clutch, which controls the drum 43, will be operated to such an extent as to maintain the cutter bar 46 perpendicular to the mine face as the mining machine is slid across the floor cutting a horizontal kerf. While the cutting action is taking place, the coal cuttings will be directed rearwardly over the top of the mining machine, from the chain 41 into the pan 50 and the chute 50 thereof to the face conveyor I64. It may be necessary to move the jacks 4| and 44 once or twice before the complete horizontal out has been made.

When the mining machine has been fed approximately to the other rib of the mine, the jacks 4| and 44 will be moved to a position rearwardly of said mining machine, as illustrated in dotted lines at the top of Fig. 16, whereupon the drums 40 and 43 may be operated, as previously described, to move the mining machine away from the room face and to complete the cutting of the kerf. Thereafter, the mining machine may be slid across the floor to the other side of the room by anchoring cable 44 to a jack positioned at said other side of the room and effecting an operating connection to the handling or hauling drum 43. Under these conditions the mining machine will, of course, not perform a kerf cutting operation and the kerf cutting chain will be disconnected from the motor by operating the lever 14. This hauling movement will be relatively rapid due to the relatively high speed of operation of the drum 43 which may be effected by applying appreciable braking action to the drum I08 by operating the hand wheel I58.

After the mining machine is thus returned to the starting position, the coal will be shot down and loaded by hand onto the face conveyor IE4, by which it will be delivered to the room conveyor I14, as aforesaid. Thereafter, the face conveyor 164 may be moved forward and the room conveyor I14 extended, which may be followed by appropriate propping of the mine roof to prevent cave-ins. The above described operation may be repeated in continuing the mining of the coal.

It should be particularly noted that the pulleys 42 and 45 from which the ropes 4| and 44 extend, respectively, are located closely adjacent to the bottom of the frame B of the kerf-cutting unit, so that approximately horizontal pulls will be exerted on the anchorages 4i and 44 during the feeding operations along the working face as illustrated in Fig. 16. By lowering the kerfcutting unit toward the bottom of the machine, the pulleys 42 and 44 will also be lowered and by removing the auxiliary pan 25 to permit the machine to be fed by sliding the skid 20 over the mine bottom, the ropes 41 and 44 will extend from their anchorages approximately horizontally over the mine bottom to the winding drums. However, by reason of the relatively large width of the skid pan measured in the direction of feeding travel of the machine, the contacting area of the bottom of the skid is rendered sufficiently large to effectually prevent undue tilting of the machine during feeding operations even when the kerf-cutter is adjusted for operation in its highest plane.

It should also be noted that by reason of the use of the separate control box I15, the latter may be located in the space available rearwardly of the row of roof props 246 shown in Fig. 16. Since the housing of the control box I15 entirely encloses all of the electric switch mechanism shown at the left of the loop I90 in Fig. 19, such housing affords a flame-proof casing for such electric switch mechanism. The motor 29 and the switch mechanism shown to the right of the loop I90 in Fig. '19 are also enclosed in flame-proof casings.

Therefore the system, the operation of which is diagrammatically illustrated in Fig. 16, is well adapted for use in gaseous coal mines.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and I wish therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

1. In mining and loading apparatus, the combination with a short-wall kerf-cutting unit, of an elongated conveyor, a controlling unit flexibly connected to said kerf-cutting unit and adapted to occupy a position remote from the working face, and means for feeding the kerf-cutting unit along the space between said conveyor and said working face.

2. In mining and loading apparatus, the combination with kerf-cutting apparatus comprising a plane kerf-cutter supported in top cutting position, of mechanism for feeding the kerf-cutting apparatus, and means for directing cuttings produced by said kerf-cutter from the face of the mine vein over the top of the machine and off the rear end thereof.

3. In mining and loading apparatus, the combination with a short-wall mining machine, of an elongated conveyor spaced from the working face in parallelism therewith, means for effecting feed of said mining machine along the space between the working face and said conveyor, and mechanism for effecting delivery of cuttings from the working face over the top of the machine to said conveyor during such feed of said machine.

4. A mining machine comprising a supporting frame of magnetic material, an electric motor within said frame in position to enable such motor to employ said frame of magnetic material as its field frame, a chain kerf-cutter comprising a cutter bar rigidly attached to said supporting frame to move bodily therewith, a nonrotatable cylindrical bearing rigidly secured to said supporting frame, a driving sprocket for the chain of the kerf-cutter and loosely mounted on said bearing for rotation about the same, and power-transmission mechanism between said motor and said sprocket and comprising a clutch surrounding said non-rotatable bearing.

5. A mining machine comprising a supporting frame, of a motor mounted in said frame, an elongated chain kerf-cutter comprising a cutter bar rigidly connected to said frame to occupy a plane spaced above the top of said motor, the axis of the motor shaft being spaced below such plane and extending transversely thereof, a driving sprocket in position in such plane to drive the chain of the kerf-cutter, a vertical non-rotatable bearing on top of the motor and fixed to said frame with its upper end in the plane of the upper surface of the cutter bar, a gear journaled on said bearing above the motor and below said sprocket, power transmission mechanism between one end of the motor shaft and said gear, and clutch mechanism for connecting and disconnecting said gear to said sprocket, said clutch mechanism comprising elements above and below said gear with one element slidable longitudinally of said bearing and the other element secured to said sprocket to rotate therewith.

6. In a mining machine, the combination with asup'porting. frame adapted to rest on and slide over a minebottom, of a kerf-cutting unit comprising a motor connected to a kerf-cutter to drive the same, mechanism adapted to slide said frame over the mine bottom to effect feed of said kerf-cutter and comprising a vertical shaft, mechanism connected to said vertical shaft to be driven thereby to adjust the elevation of the kerf-cutting unit relative to said frame, and means extending through said vertical shaft for controlling said elevation adjusting mechanism.

7. In a mining machine, the combination with a supporting frame, of a kerf-cutting unit mounted thereon for adjustment in elevation relative thereto and comprising a driving motor, mechanism driven by said motor for adjusting the elevation of the kerf-cutting unit relative to said supporting frame and comprising a driving shaft, and means comprising an actuating rod extending longitudinally through said shaft for controlling said elevation adjustment mechanism.

8. In a mining machine, the combination with a supporting frame, of a kerf-cutting unit mounted on said frame for adjustment in elevation relative thereto, spaced-apart vertical screw-threaded posts on said frame, a plurality of nuts one threaded on each of said posts, sprocket chainmechanism for rotating said nuts, a driving sprocket, a vertical shaft, motor operated mechanism for driving said shaft, a clutch at the lower end of said shaft for connecting the latter to said driving sprocket, and mechanism comprising a rod extending vertically from said clutch to the top of the machine for manually applying said clutch to effect operation of said elevation adjustment mechanism and thereby vary the elevation of said kerf-cutting unit relative to said frame.

9. In a short-wall mining machine, the combination with a supporting frame, of a kerf-cutting unit mounted thereon for adjustment in elevation relative thereto and comprising and having a motor within the forward portion thereof and kerf-cutter motor driven gearing on top of the motor, and rope drum feeding mechanism comprising driving gearing immediately back of the motor and connected to the aforesaid gearing on the top of the motor to be driven thereby.

10. In a short-wall mining machine, the combination with a supporting frame, of a motor mounted on the forward portion thereof with its axis of rotation adapted to extend transversely thereof and parallel to the working face of the mine vein, a plane kerf-cutter mounted on said frame in top cutting position and comprising a cutter bar extending transversely of said axis in a plane spaced above said motor, power transmission mechanism between said motor and said kerfcutter below the plane extending through said cutter bar, part of said power transmission mechanism being located at one end of said motor and the remainder on topof the same, and rope drum feeding mechanism for the mining machine comprising driving gearing adjacent the rear end of said motor and connected to the gearing on top of the motor to be driven thereby.

11. In a mining machine, the combination with a supporting frame, of a motor mounted thereon, cutting mechanism connected to said motor for driving thereby, feeding mechanism for the machine and comprising a hollow shaft connected to said motor to be driven thereby, elevating mechanism for said frame and comprising a controlling clutch, and mechanism comprising an actuating shaft extending through said hollow shaft to operate said clutch.

12. A mining machine comprising the combination with a supporting frame, of feeding mechanism mounted thereon and including two winding drums, motor operated mechanism for driving said winding drums and including a hollow driving shaft connected to one of said drums, a controlling clutch for the other drum, and mechanism comprising an operating shaft extending through said hollow shaft for operating said clutch,

13. A mining machine comprising a supporting frame adapted to rest on and slide over a mine floor, mining mechanism mounted on said frame, feeding and hauling mechanism comprising a feeding rope drum and a retarding rope drum, motor operated mechanism for driving said rope drums and comprising a hollow shaft connected to the feeding rope drum, and means for controlling the operations of the rope drums individually, the controlling means for the retarding rope drum comprising an adjusting shaft extending through the aforesaid hollow shaft.

14. In a mining machine, the combination with a supporting frame, of kerf-cutting mechanism comprising a cutter bar mounted on an integral forward extension of said frame, an electric motor employing as its field frame elements integral with said supporting frame, power transmission mechanism between said motor and said kerf-cutting mechanism to drive the same, motor operated rope drum feeding and guiding mechanism mounted on an integral rearward extension from said frame, and means for controlling said feeding and guiding mechanism.

15. In a mining machine, the combination with a supporting frame, of cutting mechanism mounted thereon, motor operated mechanism for operating said cutting mechanism, a master control device on said frame in position for actuation by the machine operator said control device including regular and emergency controls, and auxiliary automatic motor controlling mechanism remote from said supporting frame but connected to said master control device.

16. In mining apparatus, the combination with a short-wall mining machine comprising an electric motor to drive the operating mechanism thereof, of a motor controller, a portable flameproof casing enclosing said motor controller and adapted to rest on and slide over the mine bottom independently of the mining machine proper, a master switch, and electric circuits and connections between said master switch and said motor controller and between the latter and said motor for enabling actuation of said master switch to effect the operation of said mining machine along the working face of a mine vein while said flameproof casing rests on the mine bottom in stationary position remote from the said working face.

1'7. In mining apparatus, the combination with a short-wall mining machine adapted to rest on and slide over a mine bottom and comprising an electric motor connected to mechanism for driving and feeding a kerf-cutter, of an elongated conveyor spaced from the working face in parallelism thereto, a motor controller, a portable box for enclosing and supporting said motor controller and adapted to be located remote from the space between said conveyor and the working face, and a master switch on the mining machine but connected to said motor controller by a flexible electric cable for effecting through said motor controller the operation of the mining machine'including the feed thereof along said space between said conveyor and the mine vein.

18. In a mining machine, the combination with a supporting frame, of cutting mechanism mounted thereon, motor operated means for driving said cutting mechanism, feeding and retarding rope drums mounted on said frame, motor operated means for driving the feeding rope drum and comprising a hollow shaft with a clutch mounted thereon, additional motor operated means for driving the retarding rope drum and comprising an additional clutch, and mechanism extending through said hollow shaft to said additional clutch to control the same.

19. A mining machine comprising the combination with mining mechanism including feeding mechanism having a rope drum, of a driven shaft, a clutch having a rotor element connected to said shaft to rotate therewith, a support hav ing a journal bearing for rotation of the other clutch element on the axis of said shaft, mechanism comprising a hand wheel mounted for rotation on the axis of said shaft at one side of the clutch adjacent to said rope drum, journal bearing supports for the ends of said shaft, driving gearing between said shaft and said rope drum comprising a pinion on the shaft between said hand wheel and one of the shaft end journal bearings, and power transmission mechanism adjacent to the other shaft end journal bearing and connected to the second-named clutch element to rotate the same and when the clutch is applied to effect transmission of power through said shaft and said gearing to said rope drum to rotate the latter.

20. A mining machine comprising the combination with mining mechanism having feeding mechanism including two spaced rope drums, a base frame, elevating mechanism on said base frame for varying the elevation of said mining mechanism relative to the mine bottom, power transmission means connected to said elevating mechanism and comprising a hollow driven shaft, mechanism extending through said hollow shaft for controlling said elevating mechanism, additional power transmission means driven from said hollow shaft and connected to one of said rope drums, said additional power transmission means comprising an additional hollow shaft, power transmission means comprising a controlling clutch extending from said first-named hollow shaft to the other rope drum, and mechanism extending through said additional hollow shaft to said clutch to control the same.

21. In a mining machine, the combination with a frame, of cutter mechanism extending from one end thereof, a motor having a rotor shaft extending at right angles to the axis of said cutter mechanism, means for driving said cutter mechanism from said motor comprising; a drive sprocket for said cutter mechanism, means including a large horizontally disposed drive gear for driving said sprocket, and means including a spur and bevel gears for connecting said rotor shaft and said large drive gear.

22. In a mining machine, the combination with a supporting base frame, of a plurality of spaced-apart guide posts mounted rigidly on said base frame to project upwardly therefrom, a kerf-cutting unit comprising an operating motor mounted on a supplemental frame having a horizontal bottom plate, rigid horizontal extensions from said horizontal bottom plate having an interlocking fit in said guide posts, extensions from said supplemental frame into said guide posts to have an interlocking fit therewith against lateral movement relative thereto but free to slide up and down along the same, elevating mechanism associated with said guide posts for supporting said kerf-cutting unit for adjustment in elevation along said guide posts, and mechanism connected between said motor and said elevating mechanism for operating the latter, said operating mechanism comprising a flexible driving element located in a horizontal plane at the bottom of said unit and movable up and down bodily therewith.

23. In a short-wall top cutting kerf-cutting machine having a relatively short body extending back from the coal face when the kerf-cutter projects into the coal vein, the combination with such relatively short supporting framework, of an elongated chain kerf-cutter mounted in top cutting position on top of said framework, an electric motor under the rear end of said kerfcutter with its armature shaft parallel to the coal face, a driving gear mounted on top of said motor for rotation on a vertical axis, a sprocket connected to said chain kerf-cutter and to said driving gear, power-transmission mechanism between said armature shaft and said driving gear, a feeding rope drum mounted on a horizontal axis at the advancing side of the supporting framework, a retarding rope drum on a vertical axis at the trailing side of the supporting framework, power transmission mechanism extending from said driving gear to said rope drums, the power-transmission mechanism to the retarding rope .drums comprising a vertical shaft immediately back of the motor, and means operatively connected to the said vertical shaft for effecting adjustment of the elevation of the kerfcutter.

NILS D. LEVIN. 

